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1.
The leakage and destruction of CoA in isolated mitochondria 总被引:1,自引:0,他引:1
2.
Lech Michalczuk Robert S. Bandurski 《Biochemical and biophysical research communications》1980,93(2):588-592
We have demonstrated the in vitro enzymatic synthesis of an ester of indole-3-acetic acid (IAA) and glucose and of IAA and myo-inositol by the following reaction sequence: lt]o| li]1) IAA + UDPG ? IAA-glucose +UDP li]2) IAA-glucose +myo-inositol → IAA-itmyo-inositol +glucose The enzymes were partially purified from extracts of immature kernels of Zea mays sweet corn and the two activities separated on a Sephadex G-150 column. Products were characterized, primarily, by comparison of their 70 eV mass spectra with those of authentic synthetic standards. To our knowledge this is the first example of enzymatically catalyzed acylation by a 1-O-acylsugar. 相似文献
3.
Anna Sterniczuk Elbieta I. Waajtys-Rode Anna B. Wojtczak 《Cell biochemistry and function》1991,9(1):13-21
The flux through branched-chain alpha-ketoacid dehydrogenase and the activity of the branched-chain alpha-ketoacid dehydrogenase complex were measured in hepatocytes isolated from fed, starved and alloxan diabetic rats. The highest rate of branched-chain alpha-ketoacid oxidation was found in hepatocytes isolated from starved rats, slightly lower in those from fed rats, and significantly lower in diabetic hepatocytes. The amount of the active form of branched-chain alpha-ketoacid dehydrogenase was only slightly diminished in diabetic hepatocytes, whereas the flux through the dehydrogenase was inversely correlated with the rate of endogenous ketogenesis. The same was observed in hepatocytes isolated from starved rats when branched-chain alpha-ketoacid oxidation was measured in the presence of added oleate. In both cases the diminished flux through the dehydrogenase, restored by a short preincubation of hepatocytes with insulin, was paralleled by a decrease of fatty acid-derived ketogenesis. The significance of these findings is discussed in relation to the role of insulin in branched-chain alpha-ketoacid oxidation in liver of diabetic rats. 相似文献
4.
G. Wojtczak C. Breuil J. Yamada J. N. Saddler 《Applied microbiology and biotechnology》1987,27(1):82-87
Summary The cellulase activities of six thermophilic fungi were compared. Although the thermophilic fungi grew at relatively high temperatures (>45°C) the optimum temperatures for assaying the various cellulase activities were only slightly higher than the optimum temperatures for the mesophilic fungi, Trichoderma harzianum. Over prolonged incubation (> 24 h) the thermophilic strains demonstrated a higher hydrolytic potential as a result of the greater thermostability of the cellulase components. Although the extracellular cellulase activities had similar pH and temperature optima, in some cases the thermostability of the extracellular components were considerably lower. 相似文献
5.
Inhibition of adenine nucleotide transport through the mitochondrial porin by a synthetic polyanion 总被引:5,自引:0,他引:5
The effect of a synthetic polyanion of Mr 10,000 (a copolymer of methacrylate, maleate and styrene in a 1:2:3 proportion) was studied on isolated rat liver mitochondria and on mitochondrial porin reconstituted into lipid bilayer membranes. Increasing concentrations of the polyanion inhibited the adenyl kinase located between both mitochondrial membranes in a dose-dependent fashion. Upon addition of the detergent digitonin in increasing concentrations the adenyl kinase activity was fully reversible. In reconstitution experiments with mitochondrial porin the polyanion increased the voltage dependence of the pore in such a way that the pore is switched into the closed state at much smaller voltages than in the absence of the polyanion. The asymmetric addition of the polyanion resulted in an asymmetric shift of the voltage-dependence of the pore. If the voltage is negative at the cis-side (the side of the addition of the polyanion) the pore closed rapidly whereas it was always open for potentials of opposite polarity. The results are discussed on the basis of a modification of the gate properties of the mitochondrial porin by the polyanion and by the assumption that the closed state of the pore is not permeable for nucleotides. 相似文献
6.
7.
Lech Kufel 《Hydrobiologia》1993,251(1-3):269-274
Sedimentation at the Krutynia River inflow to Lake Kujno was closely related to hydrological regime. The highest sedimentation rates, recorded in spring, decreased during summer by two orders of magnitude. Granulometric segregation of settling seston along the inflow zone was related to differentiation of phoshorus content. Smaller particles were richer in P, producing a gradient of increasing P concentrations in the settling material. A substantial loss of P from polyphosphate and various organic fractions was found after settlement of river suspensoids. Mechanisms of P losses are discussed and possibilities of P retention within the inflow zone are considered. 相似文献
8.
E I Wa?ajtys-Rode K A Na?ecz A Sterniczuk A B Wojtczak 《The International journal of biochemistry》1984,16(6):675-680
The distribution of pyruvate between cell compartments measured in isolated hepatocytes in the presence of lactate was in agreement with delta pH across plasma and mitochondrial membranes. In isolated liver mitochondria NH4Cl decreased the transmembrane potential (delta psi) by about 14 mV, whereas no change of delta pH was observed. In the presence of lactate or alanine NH4Cl increased the mitochondrial pyruvate concentration presumably due to the inhibition of the flux through pyruvate carboxylase. In the presence of lactate or alanine changes in the amount of the active form of pyruvate dehydrogenase (PDHa) were correlated with the mitochondrial pyruvate concentration, NH4Cl increased the amount of PDHa by lowering the mitochondrial ATP/ADP and NADH/NAD+ ratios. 相似文献
9.
Bączyk Justyna Gogiel Tomasz Wolańska Małgorzata Bruczko Marta Guszczyn Tomasz Popko Janusz Romanowicz Lech 《International journal of peptide research and therapeutics》2020,26(1):271-280
International Journal of Peptide Research and Therapeutics - The progressive damage of human articular cartilage is associated with loss of integrity of its extracellular matrix components. Their... 相似文献
10.
Zygmunt Kazimierczuk Ryszard Stolarski Lech Dudycz David Shugar 《Nucleosides, nucleotides & nucleic acids》2013,32(3):275-287
Abstract The 1-β-D-ribofuranosides of several 2-trifluoromethyl benzimidazoles were prepared by the fusion method, and their conformations, particularly about the glycosidic bond, determined by 1H NMR spectroscopy. 相似文献